The processing of continuous food product into individually wrapped serving portions is desirably accomplished using automated equipment. The use of automated equipment can allow for increased manufacturing efficiencies and productivity. In one such operation, a continuous film is folded into a continuous sleeve. Food product, such as cheese, can be continuously extruded into the sleeve. Once the cheese has been extruded into the sleeve, the continuous sleeve-encased cheese can be further treated and separated into individually packaged slices by sealing and cutting of the sleeve.
One such process for the processing of continuous food product into individually wrapped serving portions involves the folding of the film into the sleeve shape using a two-part forming apparatus having a forming plate adjacent a folding tunnel. The film is unwound from a roll of film and pulled over a forming plate inclined at an angle of between 45 degrees and 75 degrees to a folding tunnel. The forming plate is wide at its base, tapering upward toward an entrance to the folding tunnel. Within the folding tunnel is a cheese extruding tube through which cheese, or other such food products, are extruded. The folding tunnel is configured to form a sleeve around the extruding tube so that the food product leaving a downstream mouth of the extruding tube is encased in a film sleeve.
To this end, the folding tunnel is configured to form the planar film into a sleeve for encasing the extruded cheese. The folding tunnel includes a pair of overlapping angled members. The overlapping angled members are staggered, such that one is contacted by the film before the other. When the film contacts the first of the angled members, one the longitudinal edges of the film is folded over the cheese extruding tube. As the film continuous to be advanced through the folding tunnel, the other of the longitudinal edges of the film contacts the other of the pair of overlapping angled members and is folded over the earlier folded portion of the film. In this manner, the planar film is folded about itself and around the cheese extruding tube. Once the cheese exits the mouth of the cheese extruding tube, the cheese is encased in the advancing sleeve and both are directed toward further operations and finishing steps, including separation into individually wrapped slices of cheese.
There are several disadvantages to the method of forming the sleeve from the film using the forming plate and folding tunnel, such as illustrated in FIG. 17. As the film is pulled over the forming plate and through the folding tube, extreme variations in force exist across the transverse width of the film between the beginning of the forming plate and the exit of the folding tunnel. These variations in force can cause the film to become destabilized as the film tends to shift lengthwise away from the regions of comparatively higher forces. When the film shifts toward the regions of comparatively lower forces, the film may become skewered on the forming plate and enter the folding tunnel at an angle, as opposed to longitudinally aligned with the axis of the folding tunnel. The film may also become skewered within the folding tunnel. Skewering of the film can cause misfeeding thereof, resulting in time consuming down-time for the machine and labor intensive removal of the skewered film and reset-up of the system. These disadvantages reduce the overall efficiency of the packaging apparatus.
Another process for the processing of continuous food product into individually wrapped serving portions involves the folding of the film into the sleeve shape using a folding tunnel having an integral folding ramp surface leading to the entrance of the folding tunnel, such as illustrated in FIGS. 18 and 19 and disclosed in U.S. Pat. No. 4,532,754. The film is unwound from a roll of film and pulled over the folding ramp, which inclined at an angle of about 47 degrees to a longitudinal axis of the folding tunnel. The folding tunnel is formed partially by folded portions of the ramp in addition other portions adjacent thereto. Within the folding tunnel is a cheese extruding tube through which cheese, or other such food products, are extruded. The ramp and the folded portions thereof are embossed with dimples in an attempt to reduce friction forces between the contact surfaces of the film and the film.
The folding tunnel is configured to form a sleeve around the extruding tube so that the food product leaving a downstream mouth of the extruding tube is encased in a film sleeve. Like the multi-part forming apparatus discussed hereinabove, the integrated ramp and folding tunnel are configured to form the planar film into a sleeve for encasing the extruded cheese. The folding tunnel includes a pair of overlapping angled members. The overlapping angled members are staggered, such that one is contacted by the film before the other. When the film contacts the first of the angled members, one the longitudinal edges of the film is folded over the cheese extruding tube. As the film continuous to be advanced through the folding tunnel, the other of the longitudinal edges of the film contacts the other of the pair of overlapping angled members and is folded over the earlier folded portion of the film. The planar film is then folded about itself and around the cheese extruding tube. As the cheese exits the mouth of the cheese extruding tube, the cheese is encased in the advancing sleeve and both are directed toward further operations and finishing steps.
There are several disadvantages to the method of forming the sleeve from the film using the integral ramp and tunnel. One disadvantage is a large variation in forces in the film at the beginning of the ramp and at the exit of the folding tube. The variations in force can cause the film to stretch and skew. Another disadvantage of the prior art integral former is its construction of a thin material. The thin material edges which could cause deformations in the film and increased friction therebetween.